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Soil Gas Monitoring Articles

Present paper deals with the identification of the cause of an explosion in a hollow space positioned below a residential building as the result of welding operations. On field investigation clearly demonstrated that the explosion was due to the ignition of a flammable atmosphere in the basement of the building. Along the trial two hypotheses were brought to the judge: (a) explosion of an ...

ABSTRACT The current advisory for active soil gas investigations in California requires leak tests to be conducted at eveiy soil gas probe while taking a sample. A leak may allow ambient ak into the sample train thus diluting the soil gas and underestimating the results. Also, the leak check compound itself may have impurities thereby contaminating the sample. The advisoiy suggests leak ...

Prior to EXO TECIfs involvement. extensive soil excavation was performed of the former gasoline UST pits followed by an unsuccessful injection using only hydrogen peroxide. EXO TECH was then contracted and mobilized to the site and installed additional injection wells and performed three small dose injections using persulfate activated with hydrogen peroxide. Due to preferential ...

A simple and easy to use radon calibration chamber of volume of 216 litres was designed and constructed for applications in calibration of radon measuring devices and for research studies. The main advantage of this chamber is that instead of using 226Ra source to generate the 222Rn inside the chamber, ...

A one‐dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water ...

Abstract Approximately 100 hectares (250 acres) were investigated as part of the passive soil gas (PSG) investigation that included multiple areas of concern. The objective of the investigation program was to rapidly identify potential source areas and guide future sampling events based on the frequency and magnitude of compounds identified in the survey. PSG sampling was the preferred ...

The unpleasant odor of drinking water is one of the major problems in many water utilities in the world. Actinomycetes have long been associated with odorous compounds. Considering the paucity of research on Actinomycetes producing odorous compounds in South Korea, presence of Actinomycetes, their molecular characteristics and ability to produce odorous compounds ...

A BEACON Passive Soil-Gas (PSG) Survey was performed at a dry cleaner site in the southeastern United States to determine if Tetrachloroethene (PCE) contamination identified beneath the dry cleaner in a prior BEACON PSG Survey was migrating off site and, if so, in which direction it was moving. This survey involved 30 field samples collected in a grid pattern. Analytical results were provided to ...

A two-person BEACON field team installed 304 PSG Samplers over a two-day period. Samplers were installed through soils, gravel, asphalt, and concrete. To accommodate field schedules, the Samplers were exposed for eight days in the field and the two-person field team required one day for retrieval of the Samplers. Survey results clearly showed where source areas are present on the site, as well as ...

Received for publication June 19, 2009. Closed chambers used to measure soil-atmosphere exchange of trace gases including nitrous oxide (N2O) and carbon dioxide (CO2) generate errors due to suppression of the gas concentration gradient at the soil-atmosphere interface. A method is described here for estimating the magnitude of flux underestimation arising from chamber deployment. The technique is ...

Air entrapment plays a significant role in controlling infiltration and observed depth to water table in shallow water table environments. The current study incorporates multi-event field measurements with varying antecedent conditions and numerical modelling, using HYDRUS-1D to quantify the variation of air pressurisation values. The observations of water table in the field data depart ...

Researchers at EPA’s National Risk Management Research Laboratory (NRMRL) in Ada, OK, are developing quality assurance (QA) measures for soil-gas and sub-slab sampling methods that help differentiate contaminant vapors due to vapor intrusion from background sources. Recent research focused on measures to identify leakage of ambient air into conventional vapor probes, which can significantly ...

Received for publication September 15, 2008. Restoration of wetland hydrology can produce ecological benefits but may have unintended consequences. We examined effects of altered water level on release of dissolved reactive phosphorus (DRP) and greenhouse gases (GHG) in soil cores from a marsh being evaluated for restoration. We also measured field concentrations of DRP and other constituents in ...

Chamber-based estimates of soil-to-atmosphere nitrous oxide (N2O) gas flux tend to underestimate actual emission rates due to inherently nonlinear time series data. In theory, this limitation can be minimized by adjusting measurement conditions to reduce nonlinearity and/or by using flux-calculation (FC) schemes that account for the so-called 'chamber effect.' The current study utilizes gas ...

Since 1993, SVE has been implemented using two designs at the TP Industrial, Inc. (TPI) site in Gardena, CA, to treat soil contaminated with chlorinated solvents. The SVE system was modified in 1997 to improve emissions control efficiency by using carbon adsorption units that treat effluent from an air-stripping system for treating site ground water. By the end of 2007, SVE had removed a ...

The soil organic matter (SOM) extracted under different vegetation types from a Brazilian mangrove (Pai Matos Island, São Paulo State) and from three Spanish salt marshes (Betanzos Ría and Corrubedo Natural Parks, Galícia, and the Albufera Natural Park, Valencia) was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The chemical variation was larger in SOM from the ...

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